Generally described, a subscriber identity module (“SIM”) is an integrated circuit, used to authenticate subscribers' mobile telephony devices, such as their mobile phones. Each mobile telephony device has a unique international mobile station equipment identity (“IMEI”) number to identify the device. Typically, a SIM card is made of plastic and includes a SIM circuit and application. A universal integrated circuit card (“UICC”) is a smart card which can be used in global system for mobile communications (“GSM”) and universal mobile telecommunications system (“UMTS”) networks. A UICC is used in mobile telephony devices and ensures the security of personal data. A SIM card can be considered a type of UICC card. Although there are some technical differences between a SIM card and UICC technology, the differences are not germane to the present disclosure. Thus, the term SIM cards, as used herein, should also be understood to encompass UICC technology.
Since the first full-size SIM card, the card size has become smaller, resulting in so-called mini-SIM, micro-SIMs, and nano-SIMs. Most recently, embedded-SIMs have been developed for mobile to mobile (“M2M”) applications. Unlike conventional SIM cards, which can be physically removed quite easily from a mobile device and then transferred to a different device, embedded SIM (“eSIM”) cards are soldered directly onto a circuit board during manufacturing. The Apple iPhone® is an example of a mobile device with an eSIM card.
Unfortunately, SIM cards have many shortcomings. For example, an embedded SIM card is not easily ported from device to device. As another example, non-telephony devices, such as computers, tablets, etc., that are not physically configured to receive a SIM card cannot be used on a carrier network that relies on SIM cards for authentication. Consequently, it is difficult for a subscriber to migrate over to different devices when using a carrier network.